File copies from OS X Yosemite to Parallels 10/11 Windows Server 2008 R2 Standard VM are slow

Several of my colleagues and I develop on Macbook Pros with OS X Yosemite and run Parallels 10/11 with a Windows Server 2008 R2 Standard VM for our server environment. We all have Parallels 10 installed and ever since the upgrade to Parallels 10/Yosemite the file transfers FROM osx TO windows have intermittent copies that last about 2 minutes when they should only be taking a second or two. This only happens if the file transfers are initiated from the mac side from either the finder or the terminal.

If we initiate the copy from windows explorer this never happens. Unfortunately we are running scripts on the mac side that build and deploy our code to the Windows Server VM. This happens around 40% of the time and some of our builds run multiple copies, so tasks that should take a few seconds can take over 10 minutes waiting for the file copy to "complete".

Has anyone else experienced this and found a workaround? I have discussed with support and they said I should re-install parallel tools and fix any file system errors, but this does not solve the problem.

FYI this didn't happen with OSX Mavericks and Parallels 9.

 

An upgrade to El Capitan fixed this for me. It must be something specific to Yosemite that was causing this.